Zigzag spring unit having open supporting end



Jan. 4, 1955 H. c. FLINT 2,698,650 ZIGZAG SPRING UNIT HAVING OPENSUPPORTING END Filed April 19, 1949 2' Sheets-Sheet l INVEN I fi yzafidC 7 BY m4, 9

Jan. 4, 1955 H. c. FLINT 2,698,650 ZIGZAG SPRING UNIT HAVING OPENSUPPORTING END Filed April 19, 1949 2 Sheets-Sheet 2 9 INVENTOR. 291 6?178/95 l l i United States Patent() ZEGZAG SPRING UNIT HAVING"OPENSUPPIJRTING END Hyland C. Flint, Birmingham, Mich. assignor to 'AmericanMetai Products Company, Detrit,.Mich., a corporation of MichiganApplication April 19, 1949, Serial No. 88,294 6 Claims. (Cl. 155-179)This invention relates to spring constructions embodymg a plurality ofpre-arched sinuous or 'zigzag spring strips of the type disclosed andclaimed in KadenReissue Patent No. 21,263 and, in particular, refers tosuch a spr ng strip per se. The present application refers to springstrips for use in seat constructions and is'related to Serial No.89,114, filed on April 22, 1949,.entitled Zigzag Spring Unit HavingClosed Supporting End which refers primarily to a back-construction.

As mentioned in more detail in the application just referred to, it isthe general object of the invention to provide a sinuous spring stripconstruction in which the sometimes conflicting properties of ease ofmanufacturing, spring characteristics, and spring contour are reconciledto the extent that each is improved with respect to prior art structureswithout sacrifice in another. This is accomplished by the use ofsupports for intermediate portions of the web of the spring strip, thesesupports preferably, but not necessarily, comprising rebent ends of theweb that are formed into loops of various shapes beneath the webs andare secured at their terminal points to intermediate parts of the web.These supports reduce the unit stress in the spring strip and thereforemake possible a reduction in spring wire gage to facilitatemanufacturing. They also improve the spring characteristics such asuniformity of deflection and conformability. And they also provide aconvenient means for regulating the contour of the web.

In seat constructions it is a common requirement that the front of thespring strip have substantially more depth than the rear. It is theparticular object of the invention described herein to provide a seatspring construction having the required front depth as well as thebeneficial web supports mentioned above.

illustrative embodiments of the invention are shown in the accompanyingdrawings in which:

Fig. 1 is a perspective view of a body rest device with a part of theupholstery broken away to reveal the novel spring strips;

Fig. 2 is an enlarged end elevation of a strip shown in Fig. l; and

Figs. 3-7 show modified forms of the invention.

The body rest device 1 of Fig. 1 has a seat 3 with frame rails 5 and 7at the front and near the rear thereof to which the sinuous springstrips 9 are secured by suitable means, the connection to the rear rail7 being preferably achieved by the use of clips 11 such as described andclaimed in a copending application Serial No. 88,293, filed April 19,1949, of the present inventor, entitled Spring Supporting Clip HavingLocking Tongue.

The spring strip 9 has a web portion 13 and opposite ends which are bentin a similar manner beneath the web to form resilient loops or supports15 of a desired shape. As shown in Fig. 2, the supports 15 includespacer loops 17 by which they are connected to the ends of the web 13and then upwardly concave arcuate portions 19 which are joined tointermediate portions of the web 13 by upright, rectilinear portions 21attached by clips 23 to the web. An intermediate loop 25 of the rear orright support 15 is secured by clip 11 directly to the rear rail 7 asalready indicated, but, in order to raise the front of the strip 9, thefront support 15 is connected to the front rail 5 through the medium ofa connector strip 27. The strip 27 is upwardly convex and tangent at 28to the undersurface of the arcuate portion 19 of the front support 15 towhich I The strip 27 defines an arc of somewhatless .thani90" it isconnected at a central portion by a suitable clip 29.

and its lower end is front rail 5.

It will be recognized thatthe portions of .thesupports 15 outwardlyofthe contact point 28 and rear rail 7 comprise resilient supports forthe ends of the web13 while the portions inwardly of these .pointscomprise resilient supports for the intermediate points ofthe web. Inthis particular form of support the portions 21 addlittle or. noresiliency to the support and serve primarilyas spacers because they aresubstantially perpendicular to the web By varying the shape of innerportions of the sup ports and their points of connection with the web,it is, of course, possible to achieve various effects.

In the modified strip 40 of Fig. 3 the web .42 is supported atintermediate points which are closer to the front edge thereof than inthe strip 9. In this strip the rear support 44 is connected by a spacerloop 45 to the rear end of the web 42 and extends forwardly beneath theweb in an upwardly concave manner until it intersects the web and isconnected thereto by clip 46 at a'point forwardly of the midpointthereof. The front support 48 is connected by a clip 50 to the lowerconnector strip 27 and at this connection has a rectilinear portion 52which is bent forwardly and upwardly and secured to the web 42 by clip54. The balance of the support 48 comprises an arcuate portion 56 whichis connected to the end of the web 42 by a spacer loop 58.

The sinuous spring strip 60 of Pig. 4 hasthe front and rear supports ofthe strip 40 (Fig. 3) interchanged so that support 44 is at the front ofthe web 62 and support 48 is at the rear. If desired, the end of thesupport 48 may be bent tangent to the web 62 to provide an increasedline of contact with the web forwardly of its connection thereto by theclip 54. t

The support 15 of Fig. 2 is used at the rear of the strip 70 of Fig. 5to support the rear end and an intermediate point of the web 72. Thefront support 74 of strip 70, however, is connected only to the frontend of the web, as by the spacer loop 76, and furnishes no intermediatesupport for the web. The support 74 has an upwardly concave, inwardlyextending portion 78 which is integrally joined by a spacer loop 79 tothe connector strip 27. The support 74 and the connector strip 27provide a V-shaped support, having its apex to the rear, for the frontend of the web which functions in the same manner as the front web andsupports heretofore described. However, it has somewhat moredepthbecause of the spacer loop 79.

In Fig. 6 a spring strip 80 is shown which has the front support 74 ofFig. 5 for web 82 that is integral with the connector 27, no spacer loop79 being used. The rear of the web 82 is supported by the support 48 ofFigs. 3 and 4.

While Figs. 4-6 have illustrated different arrangements of the supportsof Figs. 2 and 3 with or without V-shaped front end supports, Fig. 7shows a different form of strip 90. This strip is endless, comprising aweb 92 and a lower upwardly concave support 94 that is connected at itsends to the ends of the web 92 by spacer loops 96 so that the stripappears cigar-shaped in elevation. The connector strip 27 is connectedby a clip at 98 to a forward portion of the support 94. Intermediate websupport is provided by a strip 100 which is secured by clip 98 to thesupport 94 and connector strip 27 and extends upwardly and rearwardly toan intermediate point in the web to which it is connected by the clip102.

In each of the strips illustrated supports are provided for both theends and an intermediate portion of the web, thus endowing the stripswith the benefits hereinbefore set forth. The connector strip 27, whichis used to support the front of each of these strips, provides a furtherdegree of resiliency and therefore serves to increase the measure ofthese benefits. The web and all the supports including the connectorstrip 27 are preferably formed of sinuous wire, as mentioned, and insome cases may be formed of a single integral strip, thus facilitatingmanufacture.

Other modifications may be made within the scope of the invention, henceit is not intended to limit it to the forms shown herein.

secured .by a suitable Lclip 31 to the What is claimed is:

1. A spring strip comprising a sinuous spring web, a common support forthe front and rear ends of the web comprising a sinuous spring beneaththe web connected to the ends of the web, a support for an intermediateportion of the web comprising a sinuous spring strip between the web andcommon support and connected at its ends to intermediate portionsthereof and a forwardly and downwardly extending sinuous spring wireconnector strip connected to the support at a point spaced rearwardly ofthe front end of the web.

2. A spring strip comprising a sinuous spring web, a sinuous springsupport for the front end of the web connected to said front end andextending rearwardly beneath the web, a sinuous spring support for therear end of the web connected to said rear end and extending forwardlybeneath the web, a sinuous spring support for an intermediate part ofthe web connected to one of said end supports and extending upwardlyinto operative engagement with the web, and a forwardly and downwardlyextending connector strip connected to the support for the front end ofthe web at a point spaced rearwardly of the front end of the strip.

3. In a seat construction the combination of a frame having front andrear transverse rails, transversely spaced sinuous spring strips havingwebs above the rails, sinuous spring portions connected to the ends ofthe webs and extending therebeneath to provide resilient supports forthe ends of the webs, sinuous strips interconnecting at least some ofsaid supports and intermediate portions of the webs, means connectingthe supports for the rear ends to the rear transverse rail, forwardlyand downwardly extending connector strips operatively connected to thesupports for the front ends of the webs at points spaced rearwardly ofthe front ends, and means connecting the lower ends of the connectorstrips to the front rail.

4. The invention set forthin claim 3 wherein said rear rail is spacedsubstantially forwardly of the rear ends of the webs and the springportions at the rear ends of the webs extend forwardly to saidconnecting means.

5. A spring element constructed from a zigzag spring strip having aseating portion, with the ends of the strip reversely bent thereunder toform supporting portions the inner ends of which project upwardly intoengagemen with the seating portion, and an additional zigzag springstrip supporting portion connected to one of said first supportingportions and extending downwardly below the front end of the seatingportion.

6. A spring element made from a Zigzag spring strip having a seatingportion, with the ends of the strip reversely bent thereunder, at leastone of said reversely bent portions extending upwardly into engagementwith the seating portion to provide additional support therefor, and anadditional spring supporting portion connected to one of said reverselybent portions and extending downwardly beneath one end of said seatingportion.

References Cited in the file of this patent UNITED STATES PATENTS1,814,789 Dorton July 14, 1931 2,116,402 Menge May 3, 1938 2,186,548Lotz Jan. 9, 1940 2,386,456 Haberstump et a1. Oct. 9, 1945 2,526,183Williams et a1. Oct. 17, 1950 2,571,184 Bateman et a1. Oct. 16, 19512,591,185 Neely Apr. 1, 1952

